The present invention relates to the field of telephone sets and more particularly to a device for detecting the hooking off of a telephone handset.
Actually, a significant effort is made in designing telephone sets to render them aesthetical so that they harmonize with the environment where they are to be used.
Thus, since a few years, there are telephone sets wherein the telephone handset, instead of actuating metal parts protruding from the base, lies on a cradle, a portion of which comprises a key actuated by hooking off or hooking on the handset for acting on a line pick-up switch.
For example, a telephone set may comprise a line pick-up switch, a contact of which is integral with the base and the other contact with a portion of the cradle, which causes connection and cleanliness problems for the non-protected contacts.
On the other hand, in order to reduce the size of telephone sets and to improve their reliability, the various electric and electronic components necessary for the operation of these sets are actually generally arranged on printed circuits arranged in the telephone body. Thus, logically, one has been compelled to use line pick-up switches set on a printed circuit and actuating the handset detection key causes, through possible intermediate levers, triggering of the switch.
Due to the arrangement of the switch on a printed circuit, various requirements appear. Indeed, the transmission of the motion between the key and the switch arranged on the printed circuit necessitates a determined relative positioning between this key and the integrated circuit and constrains the switch position on the integrated circuit, if it is desired to obtain a simple and reliable mechanical operation. On the other hand, the portion of the key that protrudes from the telephone body must be aesthetical to match the general aspect of this set, which often implies the use of materials having the same quality and same colour as the remaining portion of the base frame. However, such a material may not have the same desirable mechanical characteristics for the transmission of the displacement towards the switch. Therefore, it has sometimes been necessary to incorporate additional reinforcement or transmission parts which increase the final cost of the product.